电磁屏蔽织物技术发展概况专利分析

电磁屏蔽织物按照吸收材料的种类分为耐辐射纤维,导电吸波纤维和银纤维,文章通过对上述种类的吸波材料专利申请情况进行分析,可以得出目前电磁屏蔽织物发展概况,为我国相关行业提供参考。     

辐照对三元乙丙橡胶性能老化最新研究展望

随着国内各领域的发展需求,对作为辐射防护材料的三元乙丙橡胶提出了更高的要求,即具有较高的辐射屏蔽效果和优良的耐辐照性。简要综述了三元乙丙橡胶的辐照机理,并探讨了三元乙丙橡胶辐照前后性能变化,最后总结了提高三元乙丙橡胶耐辐照性能几种途径。     

PP／Exact共混体系耐辐射性能的研究

以共聚医用聚丙烯(PP)为基材,用茂金属催化的多功能性乙烯和α烯烃共聚物弹性体(Exact)对其进行增韧改性,研究了在γ射线辐射条件下,Exact对PP耐辐射性能的影响,并比较了PP/Exact和PP/SEBS两种共混体系的耐辐射性能,材料的耐辐射性能通过辐射前后材料力学性能的变化来评价。结果表明：添加Exact后,PP的耐辐射性能和后期效应有明显提高。为了保证材料的使用性能,PP/Exact共混体系中Exact含量为25%时,PP的耐辐射效果最佳；SEBS对PP的耐辐射改性效果优于Exact。     

SEBS对PP耐辐射性能的影响

以共聚医用聚丙烯(PP)为基材,用氢化苯乙烯-丁二烯-苯乙烯嵌段共聚物(SEBS)对其进行增韧改性,研究了在γ射线辐射下,SEBS对PP耐辐射性能的影响。材料的耐辐射性能通过辐射前后力学性能的变化来评价。研究结果表明:PP基材经过40 kGy辐射后,其断裂伸长率和冲击强度明显降低,分别从651．2％和4．35 kJ／m2下降到 189．8％和3．01 kJ／m2;SEBS的加入可以显著提高PP的耐辐射性能;不同配比的PP／SEBS体系,其耐辐射性能和后期效应不同,PP／SEBS质量配比为90:10时,共混物的耐辐射性能最佳,材料的综合性能可以满足实际应用需求。     

高性能聚酰亚胺电磁屏蔽材料的研究进展

电磁信号之间的干扰和混乱已成为当今5G无线通信时代的首要挑战，研发有效、屏蔽高、低频电磁干扰的高性能电磁屏蔽材料已成为当前的研究热点。未来电磁屏蔽材料将朝着超薄、柔性化、轻质化、宽频高效吸收、耐高温、力学性能好等方向发展。聚酰亚胺（PI）因其具有质量轻、可柔化、机械性能好、热学稳定性好等特点，常被用作高性能电磁屏蔽复合材料的基体材料。该文介绍了PI电磁屏蔽材料的屏蔽机理，重点总结了其屏蔽性能的影响因素及研究进展，并阐述了高性能PI电磁屏蔽材料未来的发展趋势。     

PVC-PE复合辐射屏蔽材料

美国辐射屏蔽技术公司近期开发成功一种由PVC-PE复合辐射屏蔽材料。首先研究改进PVC和PE性能,即通过使用一种特殊处理聚合物基体,使之产生一种电子共振效能来吸收辐射,然后将该基体黏结在天然或合成无机材料夹层中间,制成纤维品。采用该种纤维能制造核防护衣、生物与化学防护衣。PVC-PE复合辐射屏蔽材料@王沛喜     

PA66化学镀Ag、Ni电磁屏蔽材料的制备及性能研究

以PA66(尼龙66)织物为基材,通过预处理后化学镀Ag、Ni的方法制备表面均匀、质量轻、耐蚀性好、屏蔽效能高的复合电磁屏蔽材料。研究了PA66表面化学镀Ag、Ni、Ni-Ag和Ag-Ni,分别用SEM分析了制备材料的表面形貌,用综合物性测量仪测试了磁滞回线(VSM),用法兰同轴测试仪测试了屏蔽效能(EMSE),用电化学工作站测试了材料耐腐蚀性能(Tafel),结果显示PA66-Ag/Ni具有最好的耐蚀效果,该复合电磁屏蔽织物面密度只有66g/m~2,而屏蔽性能最高可达71dB,在同类型低密度电磁屏蔽材料中具有优异的性能。     

耐辐射无卤阻燃线缆材料的制备

将氢氧化镁/红磷/乙烯-醋酸乙烯共聚物(EVA)体系作为无卤阻燃材料主体,通过加入蒙脱土(MMT)和耐辐射助剂共混制备复合材料,以减小红磷用量,降低成本,增强材料的阻燃性能和耐辐射性能。重点考察了蒙脱土对复合材料的拉伸性能、阻燃性能、加工流动性的影响。另一方面,研究了双酚类抗氧剂对材料耐辐射性能的影响。结果表明,材料的拉伸性能、阻燃性能、耐辐射性能达到核电站线缆要求。     

功能化碳纳米管/环氧树脂多孔复合材料制备及电磁屏蔽性能

以马来酸酐（MA）为功能性单体,通过自由基反应制备了马来酸酐功能化的多壁碳纳米管（MA-MWCNT）;以MA-MWCNT、环氧树脂、蓖麻油酸改性的四乙烯五胺固化剂、釉粉、水为原料,通过悬浮乳液聚合法制备了功能化碳纳米管/环氧树脂多孔复合材料。采用拉曼光谱、X射线衍射、红外光谱、X射线光电子能谱对功能化的碳纳米管进行了表征和测试。采用扫描电镜（SEM）、表面电阻测量仪、矢量网络分析仪对复合材料的表面形貌、电导率和电磁屏蔽性能进行了测试。结果表明：马来酸酐功能化单体的引入能够很好地改善碳纳米管的分散性能及材料的电磁屏蔽性能;随着碳纳米管含量的增多,复合材料的电导率增大,电磁屏蔽效能峰值增大,材料的电磁屏蔽性能增强;加入功能化的碳纳米管比加入未功能化碳纳米管的电磁屏蔽性能高,多孔复合材料比无孔复合材料的电磁屏蔽性能高。当加入功能化的碳纳米管的量为3%时,制备得到的多孔材料电磁屏蔽性能最佳,其电磁屏蔽性能峰值达到31.1dB。     

高速动车组牵引电机匝间绝缘的纳米氧化铝制备及性能分析

针对传统高速动车组牵引电机采用单层聚酰亚胺(PI)薄膜作为主要绝缘材料存在的老化问题,采用原位聚合法对纳米氧化铝进行制备.制备过程中将PI作为基体,纳米氧化铝粒子作为无机填料,形成纯PI薄膜以及纳米氧化铝复合薄膜.为验证该材料的老化性能,利用电晕老化试验系统对纳米氧化铝复合薄膜的老化性能进行测试.测试结果表明:该复合材...     

Flexible Low-Melting Point Radiation Shielding Materials: Soft Elastomers with GaInSnPbBi High-Entropy Alloy Inclusions

A polydimethylsiloxane (PDMS) matrix soft elastic composite material with low-melting-point GaInSnPbBi high-entropy alloy (LHEA) inclusions is prepared to evaluate its radiation shielding performance. The LHEA is composed of two different three-component eutectic microstructures, which are grown in a mixed manner to form a complex eutectic structure. The inclusions have excellent mechanical properties that matched the deformation of the PDMS matrix. To evaluate the interaction of the shielding material with photons, the Monte Carlo N-Particle Extended and XCOM codes are used to determine the shielding parameters of the LHEA/PDMS composites, such as mass attenuation coefficient, linear attenuation coefficient, half-value layer, tenth value layer, mean free path, and effective atomic number. The composite with 50-vol% LHEA has the best radiation shielding properties, validated by medical X-ray imaging experiments. The excellent shielding properties of the flexible lightweight composites are attributed to the higher mass attenuation coefficient of the LHEA inclusions than that of lead.     

核辐射屏蔽用胶粘剂的理论计算研究

利用蒙特卡罗数值模拟法(MC法)、查表法对核辐射屏蔽用胶粘剂的屏蔽效果进行了理论计算和实验验证。研究结果表明,当采用宽束模型进行计算时,搀杂碳化硼和胶粘剂后的屏蔽材料对γ射线(由~(137)Cs发出)的衰减倍数为3.02;当采用窄束模型进行计算时,搀杂碳化硼和胶粘剂后的屏蔽材料对γ射线(由~(137)Cs发出)的衰减倍数为3.31。当核辐射屏蔽材料的组成与配比为m(铅)∶m(碳化硼)∶m(胶粘剂)=90∶5∶5时,辐射屏蔽材料(20mm厚)对~(252)Cf中子的衰减倍数为1.7,对γ射线(由~(137)CS发出)的衰减倍数为2.7,均与理论计算值接近。因此,利用MC法、查表法指导核辐射屏蔽胶粘剂的制备是可行的。     

Microstructure and properties of WB/Al nuclear shielding composites prepared by spark plasma sintering

In this paper, a novel nuclear shielding material capable of shielding neutrons and gamma rays, WB-reinforced Al (WB/Al) composites, was prepared by spark plasma sintering (SPS) process. The microstructure of the composites was characterized, and the effects of WB content, heat treatment and matrix type on the properties of the composites were discussed. The results demonstrate that the WB particles are uniformly dispersed in the aluminum matrix and formed a good binding interface with the matrix. WAl₁₂ as an interfacial reaction product is identified, and segregation of Si and Mg elements at the reinforcement/matrix interface occurs. The mechanical properties of the WB/Al composites are sensitive to the WB content. The hardness, elastic modulus and bending strength of the composites increase monotonously as the WB volume fraction increasing, up to 234%, 107% and 91.6% higher respectively than those of the monolithic 6061Al. However, the tensile strength reaches a peak point when the volume fraction is 20%. The effects of T6 treatment and matrix type are not pronounced, especially for the composites with high WB content. The thermal neutron and gamma ray shielding properties of the composites both increase with the increase of material thickness and WB content. The WB/Al composites developed in this work show good application prospects in the field of nuclear radiation protection, due to their good mechanical properties and well neutron and gamma-ray shielding performance.     

磷酸盐基碳化硼陶瓷多层涂层的制备

实验以磷酸盐粘结剂作为基料、碳化硼粉末作为主要骨料制备出磷酸盐基碳化硼核辐射屏蔽涂层,对实验结果进行了XRD和SEM检测,并作分析.通过改变涂料成分配比,确定最合适的骨料配方为：Al2O3∶SiO2∶B4C=2∶1∶6,最合适的烧结温度约在500℃左右,并用新方法配置了磷酸盐粘结剂,实现了H3PO4∶Al（OH）3=3∶1的最佳配比,大大缩短了配置粘结剂所用的时间,制备了磷酸盐基碳化硼核辐射屏蔽多层涂层.     

树脂纳米铈防辐射复合材料的制备及其性能研究

利用强酸性苯乙烯系阳离子交换树脂制备防中低强度的X射线辐射的树脂纳米铈复合材料,用透射电镜观察它的粒度和形貌,发现铈粒径在20nm左右且分布均匀。利用具有中低强度的X射线的CT扫描仪对该种树脂纳米铈复合材料扫描,发现在相同含量的条件下树脂纳米铈复合材料比普通硝酸铈对X射线的衰减能力高许多。另外由于纳米铈的小尺寸效应和特殊的轨道特征,树脂纳米铈复合材料还可作为增感屏使用,是一种具有多功能的防辐射材料。     

Flexible X‐ray radiation protection membrane PVA/pb(NO3)2 microcapsule composites supported by bacterial cellulose

Flexible and nonpoisonous X‐ray‐shielding membranes supported by bacterial cellulose (BC) were prepared, in which X‐ray‐shielding materials were of microcapsule structure by using polyvinyl alcohol as shell and lead salt as core. The effect of the wall/core interaction and the amount of cross‐linking agent were taken into consideration to find the optimal reaction conditions. The morphology, microcapsule size, and lead salt release properties were investigated. After supported by BC, the flexible and potable membranes for X‐ray radiation protection were prepared and the shielding properties were evaluated, which indicated a good X‐ray‐shielding material. We set up a new method to prepare flexible and portable X‐ray radiation protection membranes. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43120.     

电磁屏蔽材料用银包玻璃微珠核-壳粒子的制备及其性能

采用自组装化学镀银技术制备了银包玻璃微珠核-壳粒子,并且运用X射线衍射仪、扫描电镜和电子能谱仪等对该核-壳粒子的物相和形貌等进行了表征.分析了该核-壳粒子的介电性能与结构的关系,并以此为屏蔽填料,研究了电磁屏蔽涂料的相关性能.结果表明,银粒子在玻璃微珠的表面包覆均匀且致密,该粒子的介电常数较包覆前大幅度提高.该电磁屏蔽涂料的导电性能随着填料的体积分数(下同)的增加而增加,达到25%时,其表面电阻率为0.050 7Ω/cm2.同时,在电磁波的频率范围为30～1 500MHz时,屏蔽效能达40～65 dB,并且该材料具有较好力学性能和耐环境性能.     

2D Ti3C2Tx MXene/aramid nanofibers composite films prepared via a simple filtration method with excellent mechanical and electromagnetic interference shielding properties

Electromagnetic shielding (EMI) materials are becoming more and more important because of the increasingly serious radiation pollution. The preparation of high mechanical strength, ultrathin, lightweight, flexible materials with excellent EMI shielding performance have so far been elusive. Here, we try to prepare an ultrathin, lightweight and flexible film with excellent EMI shielding performance using one-dimensional aramid nanofibers (ANFs) and two-dimensional few-layered Ti₃C₂T_x through a simple filtration method. The ultimate tensile strength and strain of the film are up to 116.71 MPa and 2.64%. The EMI shielding effectiveness and the specific EMI shielding efficiency are 34.71 dB and 21971.37 dB cm² g⁻¹, which will be no recession after 1000 times bending. Our results show that a practical EMI shielding material with excellent performances has been successfully prepared, which will be widely applied in wearable electronics, robot joints, and precision instrument protection and so on.     

Super-elastic carbon-bonded carbon fibre composites impregnated with carbon aerogel for high-temperature thermal insulation

A novel super-elastic carbon fibre composite was prepared by impregnating carbon aerogel into carbon-bonded carbon fibre (CBCF) through vacuum impregnation. The compressive strength of CBCF-CA was increased to 1.24?MPa in the z-direction, which was 6-fold more than that of neat CBCF. The CBCF-CA spontaneously recovered its size and shape without significant deformation when the pressure was released. The thermal conductivity of CBCF-CA was 0.246?W?(m·K)^?1 at 1400°C in the z-direction, which is lower than that of CBCF (0.341?W?(m·K)^?1). The average electromagnetic interference shielding e?ectiveness of CBCF-CA composites in the range of 12.4–18?GHz was higher than 40?dB, suggesting an absorption-dominant shielding feature. The CBCF-CA composite will be a new multifunctional material due to its low density, low thermal conductivity, high specific strength, excellent processability, super-elastic property and high electromagnetic shielding, which can be used for thermal insulation and protection of aerospace.